Re: [PATCH] tty: only print sysrq help for handlers that are enabled

From: Greg Kroah-Hartman
Date: Thu Dec 12 2013 - 21:30:58 EST


On Tue, Dec 03, 2013 at 07:55:25AM -0800, Shawn Landden wrote:
> Also print out a notice when sysrq is in selective mode.
>
> Signed-off-by: Shawn Landden <shawn@xxxxxxxxxxxxxxx>
> ---
> drivers/tty/sysrq.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
> index ce396ec..4eee0e4 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -548,9 +548,14 @@ void __handle_sysrq(int key, bool check_mask)
> ;
> if (j != i)
> continue;
> - printk("%s ", sysrq_key_table[i]->help_msg);
> + /* only print if handler is enabled */
> + if (sysrq_enabled & 1 ||
> + sysrq_enabled & sysrq_key_table[i]->enable_mask)
> + printk("%s ", sysrq_key_table[i]->help_msg);
> }
> }
> + if (!(sysrq_enabled & 1))
> + printk("(some options are disabled)");
> printk("\n");
> console_loglevel = orig_log_level;
> }

What exactly is this fixing? What is broken here that this change
resolves? Where is it applicable? I need a lot more context here
please.

thanks,

greg k-h
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